Svelte Mapbox-gl-draw:如何获得父组件的多边形坐标？

<script>
  import { onMount } from 'svelte';
  import mapboxgl from 'mapbox-gl';
  import MapboxDraw from '@mapbox/mapbox-gl-draw';

  let map;
  let draw;

  onMount(() => {
    mapboxgl.accessToken = 'YOUR_MAPBOX_ACCESS_TOKEN';
    map = new mapboxgl.Map({
      container: 'map',
      style: 'mapbox://styles/mapbox/streets-v11',
      center: [-74.5, 40],
      zoom: 9
    });

    draw = new MapboxDraw();
    map.addControl(draw);

    map.on('draw.create', handleDrawCreate);
  });

  function handleDrawCreate(event) {
    const { features } = event;
    const polygonCoordinates = features[0].geometry.coordinates;
    // 将多边形坐标存储在父组件的数据中
  }
</script>

<div id="map" style="width: 100%; height: 400px;"></div>